DC 12 Volt or AC 120V 240V For My Landscape Lighting System ?

Posted on August 27 2016

In our previous article, we have discussed how landscape lighting is one of the most common applications for a low-voltage lighting system, and it does come with several advantages over the high voltage alternative.

For this article , we will dig a bit deeper about the advantages and disadvantages of the two different types of voltage systems, and whether upgrading (or technically, downgrading) to lower voltage alternatives will be worth it.

We have discussed the differences between both voltages, their cost impact and functionality in our other article here, so for the basics, go ahead and take a look at our previous article to get up to speed.

Let us now discuss some important factors that will help you further understand when comparing the two systems.

1. Safety 1st.

In general, a lower voltage rating is usually the safer option. The lower the voltage, the lower the harm it brings to a human body when electrocution does occurs. In conjunction, DC current itself is a lot safer than its AC current counterpart. The real danger of low voltage electrocution are usually contingent with a very high amperage.

In a DC current system, electrocution will only occur when both receptacles are touched, even in a damp or wet setting, opposed to the AC current where lethal electrocution can happen when only one receptacle is touched.

Why does it matter for a landscape lighting application? Because you will use many metal equipment such as spades, hoes, gardening scissors, etc. Not to mention, being in a generally outdoor setting, you will be dealing with a lot of water, both from rain and artificial devices like a sprinkler.

Would the investment for a low-voltage DC system over safety reasons worth it? We'll let you be the judge. But, if you're planning to do your landscape lighting yourself without any professional assistance, we'd definitely recommend using low-voltage options for your safety.

Winner: low-voltage

2.Wiring Requirements

Depending on your country's electrical code, most will require the cables to be buried underground in an outdoor area. Even when it is not required by law, it will also be necessary for both safety and aesthetic purpose.

On a 120-volt or 240-volt system, depending on your location, burying the cable might require building an underground trench to support the electrical conduit. Check out this guide by FamilyHandyman.com for underground cable installation:

On the other hand, burying a 12-volt cable underground is far simpler, and you won't need to bury as deep as in a high-voltage system which will save a lot of installation costs. However, you will need to install transformers to convert the AC current of your household (excepting you already have a DC household).

You will also need to carefully calculate and plan the wiring size of the DC low-voltage system. You can read our in-depth guide here.

If you are building a new house, building an underground trench to support a 120/240-volt system will be easier. However, if you're remodeling an old landscape, the process might disrupt existing irrigation system, existing wires, and many other complications.

However, the low-voltage system will also have its own complications in calculating and planning the wiring and transformer size.Wire gauges also tend to be thicker in a low-voltage setting, which will be an additional cost, as well as additional weight.

Which one is the winner? Depending on your situation and needs.

Winner: tie

3. Product Selection

Low-voltage fixture and lighting selection generally come in smaller sizes, which will be perfect for a landscape application where you can mount it on smaller trees, hide it inside the bush, and so on.

Higher voltage selection, on the other hand, tends to be bulkier which may limit their application aesthetic-wise. However, you can use higher lumen lightings and permanent mountings for larger sites.

4. Efficiency And Loss

Lower voltage rating tends to have more voltage drops and losses, while it is generally more stable in a higher voltage setting.

On a large landscape site where the power source can be separated so far away from the main panel, the low-voltage system will be at a further disadvantage because of the thicker wire gauge needs. The longer the cable, voltage drops will also happen much more often.

Efficiency-wise, especially on a larger site, AC high-voltage system is the clear winner.